Many moons ago, I replaced the axle bearings on the back of the 73 Duster with a 7 1/4 rear end. I did so because they were noisy. I had jacked it up and ran it and listened with a stethoscope and found the pinion bearing quiet and the axle bearings noisy. Problem solved, no more noise. Lately the noise is back. Even worse, my son told me one day as he neared a stop sign, the car suddenly came to a HUGE stop and would not move and he heard lots of not too good noise. I removed the differential cover and found metal in there. I saw no obvious chips in the gears but noticed fluid coming from the pinion area. I cleaned it out good and filled it back up just to be able to listen. This time the noise is coming from the pinion bearing. My question is: Is the replacement of the pinion bearing something I can do properly without a lot of special tools? Is there somewhere I can find specific instructions on how to do this? I am afraid if I had someone else do it that it might be quite costly and I HATE doing that anyway. Thank you.

As long as there is no other damage- a bearing and seal replacement
at many shops should be under $300 or less with parts...

Setting the crushed sleave is the hardest part, long braker bar
and 2 people are often needed (air tools can be risky and may
over tork it and even then doing this on a floor with jack stands
can be a real b%tch).
You will need to remove the Drive gear set to replace the
pinion bearing and relash the gears (dial indecator is a must)
and a axle spreader may also be needed to get the gear set
out of the axle, as well as a puller for the pinion bearing (which is
pressed on).


How much slop is in the spider gears?
they kind of are a weak spot also and will wear
out long before the pinion/ring and can "lock"
if too sloppy(though they often brake when that happens),
before spending a lot of time and/or money
check it out really well or you may be back in there
before you know it.

New ring and pinion- with install set (bearings, seals ect...), spiders set,
can be had for around $450 (you can brake that price down
to much less depending on what you replace)....
shop local to me will do the install for around $350 for the
hole thing (axle bearings not included).....
your in there, might as well do it right......

For me, if I do it myself depends on time, if I got it- no prob,
but saving $350 it often not worth it to do it myself...
plus if it's a good shop they will back up there work,
if I do it I got to go back under to fix it if I mess it
up....

My $.02

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http://imageevent.com/jeffc
62 D100 225 3sp lwb
64 D100 A318 727pb custom lwb
66 D100 A318 4sp lwb
68 D100 B383 727 swb
65 Belveder A318 727 4d
65 Dart GT LA273 2bbl 904
73 Scamp 225 2bbl 4spOD
Old iron or no iron

If it were me, I would put that money towards a bigger rear end. I would not want to spend that much on a 7 1/4.

_________________
Excuse me, does this smell like chloroform to you?

^ Exactly. Get an 8.25" if you are going to spend money.

Sinking money into a 7.25" is counter productive in my book.
Sinking ~$400.00 into a 7.25" rear end is plain foolish.

_________________
1969-1/2 Dodge Super Bee A12 (440 Six Pack, 4-spd, Dana 60)
1974 Plymouth Duster 360 (4-spd, 8.75")
1973 Plymouth Duster (225, auto, 8.25")
2001 Dodge Ram 1500 QC 2wd (5.9L, auto, Dana 60)

Or, put the bearing in yourself.

If you have access to another 7.25 with the right gears....you might find it easier to swap the whole unit.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Thanks everyone. If I put a larger one in, is there anything else I need to change or will it pretty much slide in place? Also, would my only source be a junk yard? Thanks again.

You might well have to have the drive shaft shortened. You can snag the shaft out of the donor car if it is the same wheelbase as the receiving car.

_________________
David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

So, what if I finally get rid of the automatic tranny too. I have always though there was something wrong about automatic trannies in sports cars....not to offend anyone but I tend to be purist about some things for my own personal preference. I play bass guitar ONLY with my fingers and NEVER with a pick..same purist attitude.

Sports car.... when built they were an "economy" car! If you stay with a short tail A/F body manual trans, it won't effect driveshaft length, but may need a yoke change. I definitely agree that it's not worth spending a dime on a 7-1/4 , especially if you have to pay someone else's labor to do so! I had no less than 3 of them, offered them for a measly $25 each, drum to drum, all 2.76 ratio/open carrier; no takers. Gave 2 away and scrapped the 3rd just to get em outta here; all were "good" rear ends as in no noise/leaks, not locked up; but they were still 7-1/4s. If you get a good price on your master install kit (be cheaper that way than the individual parts) and are capable of rebuilding that rear end yourself, would be the only way to even think of doing anything with that rear end other than junking it. But as was said above, if you wind up needing a spider gear kit (get from someplace like National Drivetrain or Randys) you will definitely windup spending more than you would on a replacement rear end, even considering a possible trip to the driveshaft shop thrown in!

The other thing you might need is the lower shock mounts. When I got my 8 3/4 rear end I had to get ones that were the right size, my 7 1/4 ones didn't fit.

Yes, shock plates and U-bolts will be different, save the ones from the donor car and reuse those.
It is also a good idea to change over the emergancy brake cables, lenghts can be different.
DD

Well, as I was debating what to do. You all DID have me convinced to go with a larger rear end...on the car that is. As I was trying to find one in case this old one was indeed trashed out, my son (the Duster is his), got a job in Utah (Provo, near Salt Lake City). So, I put it in the shop for someone else to deal with since he leaves in a couple weeks. Well, they said the previous owner beat the snot out of the differential with a hammer and it was trash. The only thing they could locate on short notice was another 7 1/4 so for expediency sake, I had them replace it with that. I appreciate everyone's help. Now, another problem that I will go to another thread here for is that I discovered he will have to pass a smog test there. I couldn't find much info on their DMV site but my haste may have been premature if he can't reasonably pass the test, I may need to hang onto the car here for him or something. Thanks again. You all here have always been a super help. I wish I knew enough myself to return the favor more but I have tried to help when I could.